Takeoff is measured in hours and days. An estimator opens a drawing set, sets the scale by hand, and works page by page counting fixtures, tracing linear runs and totalling areas — then repeats the whole thing when the set is revised.
Most of a drawing set is irrelevant to any one trade. An electrical estimator does not need the landscaping sheets, but still has to open them to find out. The volume of pages is itself part of the cost.
And generic automation does not fit. Exteriors, plumbing, electrical and mechanical each count different things in different ways, so a tool that measures everything the same way produces numbers nobody can bid from.
And an estimator has to sign their name to the bid. Every competing tool returns a number in a table with nothing behind it, which is precisely why estimators do not use them — so the requirement was never accuracy alone, it was showing the measurement on the drawing and making it correctable in seconds.